1. Technical Field
This invention relates generally to the field of building construction. It relates more particularly to drywall, drywall installation equipment, and an apparatus for cleaning tools and other objects, including the tools used for drywall installation.
2. Description of Related Art
The term “drywall” herein includes panels made of a paper liner wrapped around an inner core of gypsum plaster, or the like. Such panels are also referred to as gypsum board, plasterboard, and sheetrock. Installation involves the use of various tools (i.e., “drywall tools”) to prepare and apply drywall joint compound (i.e., a fluid slurry often referred to as “mud”) in the process of taping joints between drywall panels and otherwise installing the drywall. The mud may, for example, include such constituents as water, limestone, expanded pearlite, ethylene-vinyl acetate polymer, and attapulgite that are blended in a delicate mixture having a creamy texture that facilitates application.
After applying the mud, a drywall installer (i.e., a “drywaller”) cleans the drywall tools in order to remove accumulated mud. Existing tool-cleaning techniques often proceed by simply spraying the tools with water from a hose. The water rinses the mud from the tools, thereby producing dirty water (i.e., turbid water that is cloudy due to the presence of fine particles of mud constituents suspended in the water). To comply with various laws and regulations that forbid the introduction of contaminants into the water drainage system, the drywaller often cleans drywall tools by spraying them with a hose over a barrel. The barrel catches the dirty water so that the drywaller can disposed of the dirty water in an allowable manner at a later time.
Just exactly how a drywall installer should dispose of the dirty water remains a problem, however. One way, is to use the portable apparatus called a “Drywall Tool Cleaning and Recycling Apparatus” that is available under the trademark MUDMASTER WASHMASTER from Mudmaster, Inc. of Escondido, Calif. One model of such an apparatus (i.e., a “Washmaster”) is shown in U.S. Pat. No. D665,955. In order to clean drywall tools, the drywaller sprays the drywall tools over a container portion of the Washmaster and then treats the dirty water with a water-clarifying agent and, preferably, an anti-foaming agent in order to quickly produce settled-out mud (i.e., mud constituents and/or other constituents previously in suspension) and clarified water. The drywaller wheels the Washmaster right to the drywall work area where it facilitates tool cleaning, dirty water collection, water clarification with the water-clarifying agent and anti-foaming agent, removal of the resulting clarified water, and recycling of the settled-out mud and/or other settled-out constituents.
Although a tool-cleaning apparatus such as the Washmaster is effective in many respects, the drywaller's use of “hot mud” instead of the more traditional premixed drywall mud complicates the tool-cleaning process. The term “hot mud” refers to quick-setting drywall mud that comes in a powdered form (usually in a plastic-lined paper bag to keep moisture out). It sets by an exothermic (heat-releasing) chemical reaction. Once water comes in contact with the powder, the combination of powder and water forms hot mud and begins a chemical reaction that causes the hot mud to harden. Manufacturers typically mix different amounts of hardening agents into the quick-setting drywall powder to cause it to set up (i.e., harden) in a desired time (e.g., 5-minutes, 20-minutes, 45-minutes, 90-minutes, or greater, as the drywaller may desire). Once the hot mud is hard, it will not shrink up or spread as it continues to dry, and so the drywaller acts quickly once the hot mud is mixed in order to apply it and then clean the drywall tools.
Thus, hot mud hardens in water. As a result, existing tool-cleaning techniques with existing tool-rinsing equipment that work for the more traditional premixed drywall mud are ineffective. The hot mud can become lodged in containers, pumps, and plumbing and cause severe damage.